Burco Clutch Set Up

[Scott Kneisel]

Just picked up a nice Burco wet clutch and a bunch of drums with various sprockets.

I would like to use this on my 101A but I don't know much about these and can't find too much on the web. It appears to be in great shape, has a ton of brass weights attached to the 4 arms and there is what I think is a slipper ring in there from what I have read.

Does anyone have any docs on how to set these up?
What kind of oil should I use? How full?

I also have a Horstman slipster clutch and would like to know what oil to use in that also?

Any help would be appreciated, I am new to wet clutches.
Scott

[steveohara]

Scott,

Here is a good baseline setup for your Burco...
Run four shoes in the trailing position. If you have the slotted shoes use them, otherwise use the standard full pad shoes. On the side of the shoes facing the drum install two of the weight plates per shoe with the screw holding them on in the position furthest from the pivot.
Install two more weight plates per shoe on the side facing the cover and secure them with screws on the remaining holes. If the "spring ring" is distorted and is starting to develope a square shape carefully re-shape it back to as close to round as you can get it... don't get carried away, just eyeball it and get it close.
The ring gets placed over the heads of the screws holding the weight plates on the side of the shoes facing the drum. Depending on the hub you have you will have to fine tune the spacer that goes on the crank before the drum slides on to get the end play in the clutch right.... make it about .025" of end play once the main nut is torqued up. Use at least 90 weight gear oil, heavier if you can find it. Don't buy the expensive stuff... just cheap dino oil is just fine. Fill to the bottom of the crank and have at it.
If it slips too high add more weights, if not enough take some off. For the 101 you want the clutch to engage at around 7,500 rpm. The weights come in two sizes, long and short. You want to start with the long weights.
If the shoes are worn a lot the throw of the heads of the screws will get to the point where the spring ring gets very square shape.... if you have that condition move the screws that the ring rides on to the position closer to the pivot to reduce the throw and it will keep the ring from so much deformation.
Good Luck!
Steve O'Hara

[Scott Kneisel]

Thanks Steve,
Will give this a try next season, its all over here in the northeast.

Thank you also Ron for your input on the phone today.

I should be all set.
scott

[Andy Symons]

Steve, Scott,

I'm also new to wet clutches but hope to run a Burco on my WB 820 with a 10 degree crank. The general consensus at my regular track however is to run ATF rather than gear oil. Any thoughts on this? Also, are slipper rings still available outside of running into one on eBay or a forum?

The Macs I run against are looking to lock up at 9 to 10K with their wet clutches and I hear Burco badmouthed a lot about their slipping predictably at first and then hardening up as a race goes on. ???

Andy

[Scott Kneisel]

Andy,
I have been told by Ron C who used to run Burcos back in the day, that ATF is not the hot tip for a Burco because it has additives that make the clutch slip too much due to the steel-to-steel contact. He recommended a non-detergent oil and said he used to run compressor oil in his and had real good luck. Steve says 90W gear oil which may also be good, that is what also works well in the Horstman rev grip wet 4 shoe clutches with steel shoes. The ATF works well with clutches that have fiber shoes like a Horstman slipster or a hartman.

9-10 grand hook up sounds pretty hard on the engine to me but then again, I don't race so I am looking to get reasonable performance and not shorten the lives of my prized vintage engines. Sooner or later these will not be replaceable.
Good luck,
Scott

[ted johnson]

Scott, we were running aircraft turbine oil in our Rev Grips in the Margay gearbox oil housing. Absolutely no ash when it heats up. You need a friend at the airport due to the cost, but a quart lasts a long time! Ted

[VirgLove]

Here is my experience. Metal to metal clutches like the Rev Grip and Burco do well with Gear oil the heavier the better just like Steve recommended. NEVER use something like Prolong or other synthetic oils they will impregnate the shoes and drum and make the clutch over slip and inconstient FOREVER. ATF is good for fiber to metal clutches like the Horstman Slipster, DXL and Hatrtmans. SMC oil also works well for the fiber to metal clutches but its a little pricey.

[Tom Davis]

Finding the best of both worlds should not be another competion "secret".
Maintaining 1970's equipment with 2010 technology is sometimes tough to match up.

This can make the transition a lot simpler.

http://www.royalpurple.com/prod-pdfs/max-gear-ps.pdf

TD

[steveohara]

To expand on what Virg said, the Burco and rev grips work best with heavy but low quality oil. To work well the shoes need to WEAR and anything like Prolong or the high quality synthetics that prevent wear under heavy loads and heat work against you. With real good lubricants the shoes burnish and the clutches don't pull hard and the engagement speed will be inconsistent. The cheap petroleum oils let the shoes wear and the clutches work better. If your shoes are burnished sand them down to eliminate the hard spots and get a fresh start. A belt sander is the quick way but a sheet of emery paper and a flat plate will work too.
If you have a badly burnished drum and it is a Burco or Horstman billit design you can re turn the ID to knock off the hardened material but don't cut too much out.
Steve O'Hara

[Scott Kneisel]

So Steve,
I have another question....
I have some Horstman billet drums that have great enduro sized sprockets but have grooves worn in the ID from the shoes. Do you know how much can safely be removed from the ID of the drum before the clutch doesn't hook up any more? I would like to save the drums if possible.
Thanks,
Scott